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Background: Intracavitary brachytherapy (ICBT) is essential in managing locally advanced cervical cancer. Brachytherapy as a modality has the advantage of a higher dose to the tumour with a dose fall off at the periphery as per the inverse square law. The dose per fraction is much higher than external beam radiotherapy. So proper application and dosimetry are of paramount importance to reduce late toxicity. Methods: A retrospective analysis of 69 patients who underwent three ICBT applications of 7 Gray in each fraction was done. The factors under consideration were the type of pain management (spinal anaesthesia (SA) versus conscious sedation (CS)), the initial size of the disease (bulky and non-bulky) and subsequent fractions (first fraction versus third fraction). The dosimetric parameters analysed were the doses received by points A, B and P and that of the critical organs (bladder, rectum and sigmoid colon). Results: The dose received by critical organs was comparable concerning all the factors under consideration. The dose to point P on the left side was significantly lower in the CS group than in the SA group (p -value = 0·031). Also, the dose to point P on the right side was significantly lower in the third fraction compared with the first fraction (p -value = 0·016). Conclusions: ICBT under spinal anaesthesia resulted in a higher dose to the pelvic wall. The initial size of the tumour or the subsequent fractions does not significantly affect the dose received by critical organs. [ABSTRACT FROM AUTHOR]

High dose rate (HDR) brachytherapy procedures for cervical cancer require multiple applicator insertions for multiple (typically 5) fractions of a single plan, which carries a risk for variability in applicator position between fractions. Due to applicator displacement relative to patient anatomy, the dose to nearby organs-at-risk (OARs) may vary significantly from one fraction to the next. The purpose of this study was to evaluate the effect of changes in HDR tandem and ring (T&R) applicator position on doses to nearby OARs and to present a quick and simple method to estimate doses to OARs inter-fractionally without having to perform a re-plan. Ninety CT image sets for 20 patients, ages 44 to 86, undergoing T&R-based HDR for cervical cancer were used retrospectively for this study. Measures of applicator positional and angular changes relative to the bony anatomy were obtained using image fusion in MIM software, between the planning CT (plan CT) and the CT on the treatment day (CT-TX). Dosimetric data were determined, also using MIM software, using the original (first fraction) dose distribution applied to organs at risk (rectum and bladder), transferred via rigid registration from the plan CT to each CT-TX. Bladder and rectum contours were also transferred from each plan CT to each CT-TX and were tweaked manually to match anatomy on each CT-TX and examined visually for appropriateness. Differences in translation and rotation of the T&R applicator between the planning CT and subsequent individual fractions were recorded and plotted against dose differences between each fraction of treatment and the original (first) fraction. Absolute dose (D 2cc) and volume (V 50) differences vs positional shifts were calculated and plotted, and the Pearson Product-Moment correlation coefficient between dose parameters and measured positional shifts was determined. Average dosimetric differences between planned dose and subsequent fractional doses obtained through rigid registration were 1.48 ± 1.92 Gy, 14.91 ± 11.92 cm3, 0.56 ± 0.93 Gy, and 1.77 ± 2.18 cm3 for Bladder D 2cc , Bladder V 50 , Rectum D 2cc , and Rectum V 50 , respectively. Correlation between Bladder V 50 and sagittal plane rotation gave an r2 of 0.4, showing the most correlation of all parameters studied. Bladder dose and volume increased by a maximum of about 2.7 Gy and 50 cm3 overall for Bladder D 2cc and Bladder V 50 , respectively. Bladder V 50 was most sensitive to T&R applicator displacements. We have quantified the effects of applicator positional changes on dose changes for the bladder and rectum. Even large changes in applicator position between fractions did not result in significant changes in dose to these normal tissues, indicating that adaptive re-planning is not necessary. [ABSTRACT FROM AUTHOR]

Cervical cancer is a common malignant tumor of female reproductive system. Radiation therapy is one of the main methods of cervical cancer treatment, of which brachytherapy is an essential and important part of radiation therapy for locally advanced cervical cancer. With the rapid development of imaging technologies such as computed tomography (CT) and magnetic resonance imaging (MRI), brachytherapy for cervical cancer has gradually developed from traditional two-dimensional image-guided technology to three-dimensional image-guided technology. And there are more and more treatment methods, including intracavitary brachytherapy, interstitial brachytherapy, and intracavitary combined interstitial implantation brachytherapy. We performed a PubMed search for introduce the application progress of intracavity, implantation, intracavity combined implantation brachytherapy and radioactive seed implantation, and discuss the dosimetric feasibility of internal and external fusion irradiation. [ABSTRACT FROM AUTHOR]

Accelerated partial breast irradiation with high dose rate brachytherapy treats early-stage carcinoma. Strut-adjusted volume implant applicators are inserted into the cavity post-lumpectomy. For an unstable applicator, changes in distance are seen each day between struts. If an applicator is asymmetrical with no strut movement on subsequent days, then it is stable. If an asymmetrical applicator continues to change strut distances, it is unstable. Waiting for applicator stabilization improves treatment reproducibility but increases infection risk. There is currently no consensus on stability, with ranges from 24 hours (h) to 72 h. Therefore, this study aims to determine when stability is achieved. We retrospectively reviewed 242 female breast cancer patients (2014–2022). CT was performed the same day as applicator insertion (Day 0) and repeated each treatment day. If applicators were initially asymmetrical, the distance between adjacent struts was measured, and the percentage change between the next and previous treatment day was calculated to determine how many applicators stabilized. Less than 5% change indicated stability. On Day 0, 208 out of 242 patients (86%) had stable and symmetrical applicators that maintained stability each treatment day, and 34 out of 242 patients (14%) had applicators with asymmetrical struts. Within 24 h post-insertion, 229 out of 242 (95%) patients had stabilized applicators that maintained stability on subsequent treatment days. Narrows previously suggested stability (24–72 h) to 24 h, leading to improved treatment efficiency and decreased infection risk as less time is needed to achieve applicator stability. [ABSTRACT FROM AUTHOR]

Cervical cancer is a common malignant tumor of female reproductive system. Radiation therapy is one of the main methods of cervical cancer treatment, of which brachytherapy is an essential and important part of radiation therapy for locally advanced cervical cancer. With the rapid development of imaging technologies such as computed tomography (CT) and magnetic resonance imaging (MRI), brachytherapy for cervical cancer has gradually developed from traditional two-dimensional image-guided technology to three-dimensional image-guided technology. And there are more and more treatment methods, including intracavitary brachytherapy, interstitial brachytherapy, and intracavitary combined interstitial implantation brachytherapy. We performed a PubMed search for introduce the application progress of intracavity, implantation, intracavity combined implantation brachytherapy and radioactive seed implantation, and discuss the dosimetric feasibility of internal and external fusion irradiation.

No standardized pain management protocol exists for intracavitary brachytherapy, and various methods of analgesia have been used in different countries and institutions. This study aimed to investigate the effects of pain management during intracavitary brachytherapy using nonsteroidal anti-inflammatory drugs (NSAIDs) or acetaminophen suppositories. In this single-center, prospective, observational study, patients undergoing intracavitary brachytherapy for cervical cancer completed a questionnaire survey after each brachytherapy session, which comprised questions regarding pain intensity, satisfaction with analgesia, and desire for effective anesthesia. Data analysis was performed using data from 100 brachytherapy sessions of 27 patients. The median numerical rating scale (NRS; 0–10) score for each intracavitary brachytherapy session was 3–4. The median satisfaction scale score for analgesia (5-point scale, 1–5) for each session was approximately 4. Eight patients (29.6%) answered that they desired anesthesia more effective than suppositories at any session of brachytherapy. A comparison of the high (NRS ≥ 4) and low (NRS ≤ 3) NRS groups during the first session revealed that the high NRS group tended to have higher NRS scores and lower satisfaction with analgesia during all sessions. A positive correlation was observed between tumor size and the NRS score during the first brachytherapy session. The NRS score was approximately 3–4, and satisfaction with analgesia was approximately 4 out of 5 when NSAIDs or acetaminophen suppositories were used as analgesics during intracavitary brachytherapy for cervical cancer. Although the current pain management protocol is clinically acceptable, inadequate analgesia is indicated in approximately 30% of patients. [ABSTRACT FROM AUTHOR]

Simple Summary: Randomized clinical trials show a survival benefit associated with immuno-molecular therapy (IMT) use in metastatic or recurrent cervical cancer. This study investigated IMT use and survival in stage IVB cervical cancer patients in Commission on Cancer® (CoC)®-accredited facilities. Patients diagnosed with stage IVB cervical cancer in the National Cancer Database and treated with first-line therapy with chemotherapy alone or with radiotherapy ± IMT were studied. Adjusted risks of death were estimated in patients treated with ±IMT after applying a propensity score analysis to balance the clinical covariates. There were 3164 evaluable patients, including 31% who were treated with IMT. The use of IMT increased from 11% in 2013 to 46% in 2019. In propensity-score-balanced patients, the median survival was 5 months longer with vs. without IMT. The adjusted risk of death was 28% lower following treatment with vs. without IMT. IMT was associated with a consistent survival benefit in real-world patients in (CoC)®-accredited facilities with stage IVB cervical cancer. Purpose: To investigate IMT use and survival in real-world stage IVB cervical cancer patients outside randomized clinical trials. Methods: Patients diagnosed with stage IVB cervical cancer during 2013–2019 in the National Cancer Database and treated with chemotherapy (CT) ± external beam radiation (EBRT) ± intracavitary brachytherapy (ICBT) ± IMT were studied. The adjusted hazard ratio (AHR) and 95% confidence interval (CI) for risk of death were estimated in patients treated with vs. without IMT after applying propensity score analysis to balance the clinical covariates. Results: There were 3164 evaluable patients, including 969 (31%) who were treated with IMT. The use of IMT increased from 11% in 2013 to 46% in 2019. Age, insurance, facility type, sites of distant metastasis, and type of first-line treatment were independently associated with using IMT. In propensity-score-balanced patients, the median survival was 18.6 vs. 13.1 months for with vs. without IMT (p < 0.001). The AHR was 0.72 (95% CI = 0.64–0.80) for adding IMT overall, 0.72 for IMT + CT, 0.66 for IMT + CT + EBRT, and 0.69 for IMT + CT + EBRT + ICBT. IMT-associated survival improvements were suggested in all subgroups by age, race/ethnicity, comorbidity score, facility type, tumor grade, tumor size, and site of metastasis. Conclusions: IMT was associated with a consistent survival benefit in real-world patients with stage IVB cervical cancer. [ABSTRACT FROM AUTHOR]

Introduction: Cancer cervix is the 2nd most common malignancy among Indian females with 1,23,907 new cases every year. Treatment options include radical radiotherapy wherein internal radiation plays an imperative role. Intracavitary applications in anatomically distorted uteri present a challenge and often result in sub-optimal applications. The purpose of this study is to determine the incidence of anatomically variable uterus in cancer cervix patients and the rate of intra-operative complications with Intracavitary brachytherapy (ICBT). Materials and methods: An audit of 276 biopsy-proven cancer cervix patients treated with ICBT between Jan 2019 to June 2022 was undertaken. FIGO stage I-IVA were included while metastatic and post-operative cases were excluded. All applications were done using the Modified Fletcher-Suit applicator, and planned on CT using Brachy vision 13.6.5, based on Point A. Results: 41/276 (14.9%) patients presented with anatomically variable uteri. 20/41 (48.78%) were retroverted uteri, 11/41 (26.82%) were anteflexed and 5 each (12.19%) had cervical stenosis and atrophied uteri respectively. The total number of applications performed was 120, and complications were recorded in 42 applications. There was a statistically significant correlation between the patient's age and the incidence of procedural complications, with an increased incidence of complications in the advanced age group (p-value -- 0.001). Similarly, a significant correlation was found between distorted anatomy and the incidence of complications (p-value -- 0.045). The higher rectal dose was observed in anteflexed uteri (p-value -- 0.001) while retroverted uteri was associated with a higher bladder dose (p-value -- 0.001). Conclusions: In anatomically difficult uteri, brachytherapy application is a challenge with significantly high rates of complications including perforation. Careful selection of tandem length and orientation of the uterine anatomy after the first fraction may enable better application in subsequent fractions. [ABSTRACT FROM AUTHOR]

Curative-intent radiotherapy for locally advanced and select early stage cervical cancer in the US includes external beam radiotherapy (EBRT) with brachytherapy. Although there are guidelines for brachytherapy dose and fractionation regimens, there are limited data on practice patterns. This study aims to evaluate the contemporary utilization of cervical cancer brachytherapy in the US and its association with patient demographics and facility characteristics. We retrospectively analyzed clinical covariates of cervical cancer patients diagnosed and treated in 2018–2020 with curative-intent radiotherapy from the 2020 National Cancer Database. Associations between patient and institutional factors with the number of brachytherapy fractions were identified with logistic regression. Factors with association (p < 0.10) were then included in a multivariable logistic regression model. All tests were two-sided with significance <0.05 unless specified otherwise. Among the eligible 2517 patients, 97.3% received HDR or LDR and is further analyzed. More patients received HDR than LDR brachytherapy (98.9% vs 1.1%) and intracavitary than interstitial brachytherapy (86.4% vs 13.6%). The most common number of HDR fractions prescribed were 5 (51.0%), 4 (32.9%), and 3 (8.6%). After adjusting for the other variables in the model, ethnicity, private insurance status, overall insurance status, and facility type were the only factors that were significantly associated with the number of brachytherapy factions (p < 0.0001, p = 0.028, p = 0.001, and p < 0.0001, respectively, n = 2184). In the US, various HDR brachytherapy regimens are utilized depending on patient and institutional factors. Future research may optimize cervical cancer brachytherapy by correlating specific dose and fractionation regimens with patient outcomes. • Curative-intent radiotherapy for cervical cancer in the US may include external beam radiotherapy and brachytherapy. • This is the first assessment of physician practice pattern of curative-intent brachytherapy for cervical cancer in the US. • Most patients received HDR intracavitary brachytherapy and completed their radiotherapy as prescribed. • Patient ethnicity, insurance, and facility type are significantly associated with number of HDR brachytherapy fractions. [ABSTRACT FROM AUTHOR]

Introduction: This study aimed to investigate whether there is a dosimetric difference of implementing single instead of multi-computed tomography (CT) simulation treatment planning for high-dose-rate postoperative gynecological intracavitary brachytherapy (BT). Materials and Methods: Eighty patients were registered in the study. They received three BT fractions of 7 Gy/week (three CTs, three original plans). The organs at risk (OAR), the rectal wall, and the clinical target volume (CTV) were delineated. The delivered doses for the 2cc of OARs (D2cc), 1cc of rectal wall (D1cc), as well as for the 90% and 100% of CTV volume (DCTV90%, DCTV100%) were evaluated. To evaluate the values of the above parameters if the single-CT-simulation method has been chosen, the time of the first treatment plan was corrected for the decay and applied as the second and third CT, retrospectively, creating the next fractions (two revised plans). Results: No statistically significant (P > 0.05) differences were found between the original and revised plans for the OARs and CTV. However, for the single-CT-simulation method, it was noted that the dose constraints for the total rectal dose were exceeded in some cases (36.3%). Conclusion: The fact that rectal dose constraints were exceeded in 1/3 of patients with the single-CT-simulation method is dosimetrically significant. [ABSTRACT FROM AUTHOR]

Aim: Locally advanced cervical cancer is frequently treated using a combination of external beam radiotherapy and brachytherapy. Radiotherapy often leads to vaginal morbidity, which poses a significant problem. This study aims to analyze the impact of reducing ovoid loading on dosimetry. Materials and methods: We analyzed forty-five CT-based intracavitary brachytherapy plans from fifteen patients. Three plan sets were created for the 45 applications: a standard loading plan (A), a plan with reduced ovoid loading (B), and a tandem-only loading plan (C). We generated Dose-Volume Histograms and recorded dose volume parameters for the three plan sets. Results: The D90 for the Clinical Target Volume (CTV) did not show significant differences among the three plan sets (p = 0.20). The average D90 values for plans A, B, and C were 8.15 Gy, 8.16 Gy, and 7.4 Gy, respectively. No statistically significant differences were observed in D2cc bladder (p = 0.09) (average values: 6.8 Gy, 6.5 Gy, and 5.9 Gy for plans A, B, and C, respectively) and D2cc sigmoid (p = 0.43) (average values: 2.8 Gy, 2.6 Gy, and 2.4 Gy, respectively) among the three plan sets. However, there was a statistically significant difference in D2cc rectum (p < 0.001) (average values: 4 Gy, 3.3 Gy, and 1.8 Gy, respectively), as well as in vaginal dose points (p < 0.001). Conclusion: Reducing ovoid loading significantly decreased the doses to vaginal dose points and the rectum without compromising the dose to the Clinical Target Volume (CTV). Therefore, in carefully selected cases, the adoption of tandem-only loading or reduced ovoid loading could be considered to minimize vaginal morbidity following high dose rate intracavitary brachytherapy. [ABSTRACT FROM AUTHOR]

PurposeCurrently, there is a lack of patient-specific tools to guide brachytherapy planning and applicator choice for cervical cancer. The purpose of this study is to evaluate the accuracy of organ-at-risk (OAR) dose predictions using knowledge-based intracavitary models, and the use of these models and clinical data to determine the dosimetric differences of tandem-and-ring (T&R) and tandem-and-ovoids (T&O) applicators.Materials and methodsKnowledge-based models, which predict organ D2cc, were trained on 77/75 cases and validated on 32/38 for T&R/T&O applicators. Model performance was quantified using ΔD2cc=D2cc,actual-D2cc,predicted, with standard deviation (σ(ΔD2cc)) representing precision. Model-predicted applicator dose differences were determined by applying T&O models to T&R cases, and vice versa, and compared to clinically-achieved D2cc differences. Applicator differences were assessed using a Student's t-test (p < 0.05 significant).ResultsValidation T&O/T&R model precision was 0.65/0.55 Gy, 0.55/0.38 Gy, and 0.43/0.60 Gy for bladder, rectum and sigmoid, respectively, and similar to training. When applying T&O/T&R models to T&R/T&O cases, bladder, rectum and sigmoid D2cc values in EQD2 were on average 5.69/2.62 Gy, 7.31/6.15 Gy and 3.65/0.69 Gy lower for T&R, with similar HRCTV volume and coverage. Clinical data also showed lower T&R OAR doses, with mean EQD2 D2cc deviations of 0.61 Gy, 7.96 Gy (p < 0.01) and 5.86 Gy (p < 0.01) for bladder, rectum and sigmoid.ConclusionsAccurate knowledge-based dose prediction models were developed for two common intracavitary applicators. These models could be beneficial for standardizing and improving the quality of brachytherapy plans. Both models and clinical data suggest that significant OAR sparing can be achieved with T&R over T&O applicators, particularly for the rectum.

OBJECTIVE The purpose was to observe the impact of Equivalent dose of 2Gy (EQD2) for different planning technique combined with intracavitary brachytherapy (ICBT) for cervix patients and to manage the organ at risks (OARs) doses in external beam radiation therapy (EBRT) and brachytherapy to respect the EQD2 tolerances. METHODS Retrospectively, 15 patients of federation of gynecologists and obstetricians Stage IB-IVA, received a dose of 45Gy in 25 fractions with a simultaneous integrated boost of 55Gy in 25 fractions to the nodes with EBRT followed by three applications of ICBT of a dose of 8Gy, were selected. Intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) plans were created for each patient with a single iso-center with 6MV photon energy. EQD2 of D2cc, D1cc, and D0.1cc of bladder and rectum were compared for IMRT followed by ICBT and VMAT followed by ICBT. RESULTS The IMRT and VMAT plans were comparable in terms of target coverage and OARs sparing. The conformity index and homogeneity index were comparable for both IMRT and VMAT with p=0.007. In VMAT and ICBT plan the EQD2 of D2cc, D1cc, and D0.1cc for bladder were reduced 0.66%, 0.41%, and 0.41%, respectively, from IMRT and ICBT plan. CONCLUSION We recommend following VMAT and ICBT over IMRT and ICBT due to advantages of VMAT over IMRT and try to keep doses of OARs as low as possible in both EBRT and BT separately. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the treatment results with focus on local control (LC) by computed tomography (CT)-guided intracavity brachytherapy and interstitial brachytherapy (ICBT/ISBT) for locally advanced cervical cancer (LACC). Patients with LACC undergoing ICBT/ISBT at least once in our institution between January 2017 and June 2019 were analyzed retrospectively. The primary endpoint was local control (LC), and the secondary endpoints were progression-free survival (PFS), overall survival (OS), and late toxicities. Differences between patient subgroups for prognostic factors in LC, PFS, and OS were analyzed using the log-rank test. The recurrence patterns of LC were also investigated. Forty-four patients were included in the present study. The median high-risk clinical target volume (HR-CTV) at the initial brachytherapy was 48.2 cc. The median total dose of HR-CTV D90 (EQD2) was 70.7 Gy. The median followup period was 39.4 months. The 3-year LC, PFS and OS rates in all patients were 88.2%, 56.6%, and 65.4% (95% CI 50.3–78.0%), respectively. Corpus invasion and large HR-CTV (70 cc or more) were significant prognostic factors in LC, PFS, and OS. Marginal recurrences at the fundus of the uterus were detected in 3 of 5 patients in whom local recurrence was observed. Late toxicities of Grade 3 or higher were detected in 3 patients (6.8%). Favorable LC was achieved by performing CT-guided ICBT/ISBT for LACC. The brachytherapy strategy for patients with corpus invasion or large HR-CTV may need to be reconsidered. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the dose–effect relationship between the dose–volume parameters of residual gross tumor volume (GTVres) and clinical prognosis in MRI image-guided adaptive brachytherapy (IGABT) of patients with locally advanced cervical cancer in our center. Materials and method: The clinical data of 93 patients with locally advanced cervical squamous cell cancer who received external beam radiotherapy (EBRT) combined with IGABT ± chemotherapy in our center were retrospectively analyzed. The disease stage, overall treatment time (OTT), chemotherapy, and the dose–volume parameters D90, D98, and D100 of GTVres, the intermediate-risk clinical target volume (CTVIR), and the high-risk clinical target volume (CTVHR) of the patients were statistically analyzed. Kaplan–Meier and uni- and multivariable Cox regression analyses were used to analyze 2‑year overall survival (OS), progression-free survival (PFS), and local control rate (LC). A probit model was employed to assess the dose–effect relationship between the volume and dose–volume parameters of GTVres and 2‑year OS, PFS, and LC. Results: The median follow-up time was 19.6 months and 2‑year OS, PFS, and LC were 79.6%, 68.8%, and 94.6%, respectively. CTVHR D90 was an independent influencing factor for 2‑year PFS (P = 0.041); GTVresBT1 volume was an independent factor for 2‑year OS, PFS, and LC (P < 0.001). The probit model showed that at GTVresBT1 volume < 32.86 cm3, the expected 2‑year LC was > 90%; at GTVres D98 > 129.12 GyEQD2, the expected 2‑year OS was > 90%. Conclusion: Both the volume and dose–volume parameters of GTVres are promising predictors in assessment of IGABT prognosis of cervical cancer. [ABSTRACT FROM AUTHOR]

Objective: To investigate the clinical outcomes and toxicity in patients with locally advanced cervical cancer treated with supplementary applicator guided-intensity modulated radiation therapy (IMRT) based on conventional intracavitary brachytherapy (IC/IMRT). Design: A retrospective cohort study. Setting: Sichuan Cancer Hospital & Institute, Sichuan Cancer Centre, China. Population: Large high-risk clinical target volume (HR-CTV) volume (>40 ml) at the time of brachytherapy cervical cancer patients were recruited. Methods: This study is a retrospective analysis of 76 patients with locally advanced cervical cancer (FIGO IIB-IVA) treated with concurrent chemoradiotherapy followed by IC/IMRT between June 2010 and October 2016. External radiotherapy (45 Gy in 25 fractions) was adminstered with cisplatin chemotherapy treatment before IC/IMRT. The IMRT plan was optimised using the ICBT plan base dose plan by an inverse dose optimisation tool which allows the use of DVH constraints on the total dose of ICBT. A seven-field gantry angle IMRT plan was devised to avoid hotspots when optimising the boost plan. The prescription dose for HR-CTV and IR-CTV were 6 and 5 Gy per fraction for five fractions, respectively. Results: Mean HR-CTV was 65.8 ± 23.6 ml at the time of brachytherapy. D90 for HR-CTV and IR-CTV were 88.7 ± 3.6 Gy and 78.1 ± 2.5 Gy. D2cc for bladder, rectum, sigmoid and small intestine were 71.8 ± 3.8, 64.6 ± 4.9, 63.9 ± 5.3 and 56.7 ± 8.7 Gy, respectively. Median follow-up was 85 months (47.9–124.2 months). Five-year local recurrence-free survival rate, metastasis recurrence-free survival rate, disease-free survival rate and cancer-special survival rate were 87.6, 82.4, 70.9 and 76.3%, respectively. The grade 1 + 2 gastrointestinal and urinary late toxicities were 15.8 and 21.1%, and grade 3 late toxicities were 3.9 and 5.2%, respectively. Neither acute nor late grade 4 gastrointestinal or urinary toxicities were seen. Conclusions: The combination of ICBT with an applicator-guided supplementary IMRT boost achieved excellent local control and overall survival with low toxicity for bulky residual cervical tumour. [ABSTRACT FROM AUTHOR]

Freehand needles can be used with multichannel vaginal cylinders (MCVC) to cover vaginal cancer >7 mm thick or with supra-vaginal extension. We report our institutional outcomes using this novel hybrid technique. Patients with vaginal malignancies treated with HDR BT using MCVC plus freehand needles from 2014-2021 at our institution were identified. Clinical characteristics, details of brachytherapy, initial response, and overall local control (LC) outcomes were recorded. LC was analyzed via Kaplan-Meier method. 34 patients were identified with median follow-up 1.9 years. 19 patients had primary endometrial cancer with vaginal recurrence/disease, and remaining had primary vaginal cancer or other primaries. 7 patients had recurrence after previous RT course. 25 patients received EBRT with median dose 45 Gy in 25 fractions, and rest received BT alone. Median HR-CTV D90 for patients treated with EBRT plus BT was 77.4 Gy. 30 patients had complete local response to BT on initial examination and/or follow-up imaging. 1 and 2-year LC rates in patients without prior RT treated with EBRT + BT were 94.1% and 94.1%, respectively. 1 and 2-year LC rates for those without prior RT were 88.1% and 76.4%, respectively. 1 and 2-year LC rates for those with prior RT were 68.6% and 34.3%, respectively. 1 patient had vaginal laceration requiring surgical repair, and 1 patient developed small bowel obstruction 1 month after BT, with no additional acute grade 3+ toxicities identified. Our approach with MCVC plus freehand needles with MRI-based planning was feasible and safe, with excellent initial local response and low rate of serious toxicities. [ABSTRACT FROM AUTHOR]

Objective: To investigate the clinical outcomes and toxicity in patients with locally advanced cervical cancer treated with supplementary applicator guided‐intensity modulated radiation therapy (IMRT) based on conventional intracavitary brachytherapy (IC/IMRT). Design: A retrospective cohort study. Setting: Sichuan Cancer Hospital & Institute, Sichuan Cancer Centre, China. Population Large high‐risk clinical target volume (HR‐CTV) volume (>40 ml) at the time of brachytherapy cervical cancer patients were recruited. Methods: This study is a retrospective analysis of 76 patients with locally advanced cervical cancer (FIGO IIB‐IVA) treated with concurrent chemoradiotherapy followed by IC/IMRT between June 2010 and October 2016. External radiotherapy (45 Gy in 25 fractions) was adminstered with cisplatin chemotherapy treatment before IC/IMRT. The IMRT plan was optimised using the ICBT plan base dose plan by an inverse dose optimisation tool which allows the use of DVH constraints on the total dose of ICBT. A seven‐field gantry angle IMRT plan was devised to avoid hotspots when optimising the boost plan. The prescription dose for HR‐CTV and IR‐CTV were 6 and 5 Gy per fraction for five fractions, respectively. Results: Mean HR‐CTV was 65.8 ± 23.6 ml at the time of brachytherapy. D90 for HR‐CTV and IR‐CTV were 88.7 ± 3.6 Gy and 78.1 ± 2.5 Gy. D2cc for bladder, rectum, sigmoid and small intestine were 71.8 ± 3.8, 64.6 ± 4.9, 63.9 ± 5.3 and 56.7 ± 8.7 Gy, respectively. Median follow‐up was 85 months (47.9–124.2 months). Five‐year local recurrence‐free survival rate, metastasis recurrence‐free survival rate, disease‐free survival rate and cancer‐special survival rate were 87.6, 82.4, 70.9 and 76.3%, respectively. The grade 1 + 2 gastrointestinal and urinary late toxicities were 15.8 and 21.1%, and grade 3 late toxicities were 3.9 and 5.2%, respectively. Neither acute nor late grade 4 gastrointestinal or urinary toxicities were seen. Conclusions: The combination of ICBT with an applicator‐guided supplementary IMRT boost achieved excellent local control and overall survival with low toxicity for bulky residual cervical tumour. [ABSTRACT FROM AUTHOR]

Purpose: To describe a novel packing technique of combining radio-opaque vaginal packing (VP) with rectal retractor (RR) blade to displace rectum and to compare the standard International Commission on Radiation Units & Measurements-38 (ICRU-38) rectal, bladder point doses and volume parameters with the conventional technique of using RR alone with tandem and ring (T&R) applicators in high-dose-rate (HDR) intracavitary brachytherapy (ICB) for cervical cancer. Materials and methods: A retrospective analysis of the treatment plans of a cohort of 24 consecutively treated patients with locally advanced cervical cancer was performed. All patients received external beam radiotherapy with a dose of 45-50.4 Gy, in fractions of 1.8-2 Gy, to the whole pelvis with concurrent weekly chemotherapy, followed by HDR-ICB. The treatment plans for each brachytherapy session using T&R applicators that these patients received were included for analysis. A total of 17 treatment plans in which the combination of RR and radio-opaque VP was used for rectum separation were included in the combination (RR+VP) group, and 21 treatment plans in which a RR alone was used were included in the conventional (RR) group. Results: The mean dose to the ICRU rectal point was 39.7% of the point A dose (range, 28.8%-50.4%; median 38.6%) in the RR+VP group and 52.7% (range, 46.9%-63.6%; median 51.7%) in the RR group. This 13% reduction in the mean dose to the ICRU rectal point was statistically significant (p = 0.001). The mean dose to the ICRU bladder point was 55.4% of the point A dose (range, 26.3%-73.6%; median 57.4%) in the RR+VP group and 45.3% (range, 23.7%-72.7%; median 46.9%) in the RR group. This 10.1% increase in the mean dose to the ICRU bladder point was also significant (p = 0.024). The other point dose and volume parameters were similar between groups. Conclusion: Compared to the conventional use of a RR blade alone for rectum separation, combining a RR blade with radio-opaque VP significantly reduced the ICRU rectal point dose. [ABSTRACT FROM AUTHOR]

Background and Purpose: Cervical cancer is the most prevalent type of cancer among women in numerous low and middle-income countries. Tandem-based applicator is a widely used technique in High Dose Rate Intercavitary Brachytherapy (HDR-ICBT) for treating cervical cancer. For cases where central tandem insertion is not feasible due to patient-specific conditions, a ring-only applicator is used as an alternative. This paper presents an assessment of the impacts of dose distribution on cervical cancer treatment using HDR-ICBT without a central tandem applicator., Materials and Method: Total 30 patients with cervical cancer (stage IB to IVA) who received brachytherapy with a ring applicator alone were singled out and used in the study. Orthogonal radiographs were used during dose treatment planning., Results: Results indicate that the dose normalized to the Equivalent dose in 2 Gy fractions (EQD2) at Manchester Dosimetry System (MDS) point A was 60.60 ± 1.08 Gy, which is significantly below the recommended curative dose of 80 Gy. This suggests that relying solely on a ring applicator may not provide enough radiation doses to the tumor. The results also show that the International Commission on Radiation Units (ICRU) dose point underestimated the radiation doses to the bladder and rectum, with the ratios of maximum dose (D Max ) to D ICRU for both organs being 1.15., Conclusion: The study underscores the importance of not exclusively depending on a ring applicator alone in HDR-ICBT treatment for cervical cancer, as it may lead to suboptimal tumor doses. The ICRU point's results show an underestimation of the rectum and bladder dose during HDR-ICBT., Competing Interests: Declaration of Competing Interest The authors affirm that they have no competing interests related to this work., (Copyright © 2024 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.)

Background: In recent few decades, the evolution in imaging technology, especially computed tomography (CT) and magnetic resonance imaging, results in widespread availability and its use in high-dose-rate (HDR) intracavitary brachytherapy (ICBT) applications. Aim: The present study was aimed to analyze the cumulative dose–volume histogram of the tumor and organs at risk (OARs) in three-dimensional (3D) CT image-based brachytherapy planning and clinical outcomes of the treated patients. Materials and Methods: This prospective observational study included 40 patients with carcinoma cervix. After external beam radiotherapy (EBRT), a dose of 6 Gy per fraction of HDR ICBT in four fractions with a total dose to point “A” approximately 80–85 Gy was given. For planning, the tumor volumes (high-risk clinical target volume [HR-CTV]) and volume of OARs (bladder, rectum, and sigmoid colon) were contoured on each CT slice. The dose–volume parameters, i.e., minimum dose received to 90% and 100% by HR-CTV volume (D90 and D100) for target and the maximum dose received by minimum volume of 2CC (D2CC) for OARs, were calculated and assessed for clinical response in patients. Results: The mean D2CC dose was 18.24 ± 0.93 Gy, 16.44 ± 1.11 Gy, and 16.37 ± 0.67 Gy for bladder, rectum, and sigmoid colon, respectively. The combined (EBRT and HDR ICBT) mean equieffective dose in 2 Gy per fraction (EQD2) dose for bladder was 76.71 ± 2.05 Gy, for rectum was 72.82 ± 2.58 Gy, and for sigmoid colon was 72.71 ± 1.41 Gy, and its comparison with baseline values showing P < 0.01 for bladder, rectum, and sigmoid colon was considered statistically significant. The mean EQD2 dose of HR-CTV D90 was 151 ± 27.3 Gy. Patients who had received HR-CTV D90 of >90 Gy compared with

Objective: Cervical carcinoma is one of the leading causes of cancer-related deaths. This study evaluates improvement of quality of life, response to treatment, and compliance of concurrent weekly cisplatin with intracavitary brachytherapy (ICRT) in patients with cervical carcinoma, pre-treated with concurrent chemo-radiotherapy. Materials and Methods: This study was conducted in the Department of Radiotherapy, Government Medical College, from October 2018 to March 2020, meeting specified inclusion and exclusion criteria; patients willing to participate in the study were included. Results: On analyzing the pattern of response, 91.0% of patients have a complete response. The incidence of nausea and vomiting was observed at grade 1 or 2 in 80.0% of patients, grade 3 in 17.0% of patients, and more than grade 3 in 3.0% of patients. Neutropenia is occurred at less than grade 3 in 30.0% of patients and grade 3 or more in 3.3% of patients. Vaginal mucositis was also observed in 85.0% of the patients in less than grade 3 and 11.6% in grade 3 or more. The incidence of renal dysfunction less than grade 3 was seen in 35.0% of the patients and grade 3 or more in 5.0% of the patients. After 6months, there was cystitis found in less than grade 3 in 10.0% of the patients and more than grade 3 in 3.3% of the patients. Conclusion: In locally advanced squamous cell carcinoma of the uterine cervix, the addition of concurrent injection of cisplatin to ICRT significantly improves locoregional response but increases the incidence of hematological and mucosal toxicity, which is manageable.

Abstract Background Image-guided adaptive brachytherapy shows the ability to deliver high doses to tumors while sparing normal tissues. However, interfraction dose delivery introduces uncertainties to high dose estimation, which relates to normal tissue toxicity. The purpose of this study was to investigate the high-dose regions of two applicator approaches in brachytherapy. Method For 32 cervical cancer patients, the CT images from each fraction were wrapped to a reference image, and the displacement vector field (DVF) was calculated with a hybrid intensity-based deformable registration algorithm. The fractional dose was then accumulated to calculate the position and the overlap of high dose (D2cc) during multiple fractions. Result The overall Dice similarity coefficient (DSC) of the deformation algorithm for the bladder and the rectum was (0.97 and 0.91). No significant difference was observed between the two applicators. However, the location of the intracavitary brachytherapy (ICBT) high-dose region was relatively concentrated. The overlap volume of bladder and rectum D2cc was 0.42 and 0.71, respectively, which was higher than that of interstitial brachytherapy (ISBT) (0.26 and 0.31). The cumulative dose was overestimated in ISBT cases when using the GEC-recommended method. The ratio of bladder and rectum D2cc to the GEC method was 0.99 and 1, respectively, which was higher than that of the ISBT method (0.96 and 0.94). Conclusion High-dose regions for brachytherapy based on different applicator types were different. The 3D-printed ICBT has better high-dose region consistency than freehand ISBT and hence is more predictable.

Abstract Background Three‐dimensional image‐guided brachytherapy is the standard of care in cervical cancer radiotherapy. In addition, the usefulness of the so‐called “hybrid brachytherapy (HBT)” has been reported, which involves the addition of needle applicators to conventional intracavitary brachytherapy for interstitial irradiation. Aim To evaluate the clinical outcomes of CT‐based HBT consisting of transvaginal insertion of needle applicators (CT‐based transvaginal HBT) and only intravenous sedation without general or saddle block anesthesia. Methods and results This is a retrospective chart review of patients who received definitive radiotherapy, including CT‐based transvaginal HBT, between February 2012 and July 2019. The inclusion criteria were as follows: (i) histologically diagnosed disease, (ii) untreated cervical cancer, (iii) International Federation of Gynecology and Obstetrics (FIGO) stage IB1–IVA disease in the 2008 FIGO staging system, and (iv) patients who underwent CT‐based transvaginal HBT at least once in a series of intracavitary brachytherapy. Overall, 54 patients fulfilled the eligibility criteria in the present study. The median follow‐up period was 32 (IQR, 19–44) months. No patient complained of symptoms such as persistent bleeding or abdominal pain after the treatment. The 3‐year local control (LC), disease‐free survival, and overall survival rates for all 54 patients were 86.6%, 60.3%, and 90.7% (95% CI [81.3%–100.0%]), respectively. The 3‐year LC rate was 87.7% in patients with FIGO III–IVA and 90.4% in tumor size >6.0 cm. The incidence rate of late adverse events, grade ≥3, in the rectum and bladder was 0% and 1.8%, respectively. In the dose‐volume histogram analyses, transvaginal HBT increased the dose of HR‐CTVD90 by ~7.5% without significantly increasing the dose of organs at risk. Conclusion Considering the favorable clinical outcomes, CT‐based transvaginal HBT may be a good option for treating cervical cancer.

Background: This study aimed to evaluate the clinical outcomes and dose-volume parameters of computed tomography CT-based brachytherapy for the vaginal recurrence of uterine cancer after hysterectomy. Methods: We evaluated 22 uterine cancer patients treated with CT-based brachytherapy for vaginal recurrence between December 2010 and August 2015. Interstitial brachytherapy (ISBT) was used when the vaginal tumor was thicker than 5 mm and/or located at extended extravaginal tissue, whereas intercavitary brachytherapy was performed if it was 5 mm or thinner. Results: Overall, 11 patients had cervical cancer, and 11 had endometrial cancer. The median pretreatment tumor size on magnetic resonance imaging was 17 mm (range, 0–45 mm). Four patients had vaginal recurrence recognized only in the gynecological examination. The primary location of recurrence was the vagina, with extravaginal extension observed in 9 patients. Seventeen patients (77%) received external beam radiotherapy and brachytherapy. ISBT was performed in 12 patients (55%). The median clinical target volume (CTV) D90 was 69.2 Gy (62.6–72.8 Gy). The median D2cc of the bladder, sigmoid, and rectum were 70.2 (63.8–77.6), 37.4 (30.0–43.6), and 52.8 Gy (38.6–63.5 Gy), respectively. Complete response was reached in all patients. The 5-year overall survival rate and local control rate (LC) were 84.8 and 95.5%, respectively. No patient experienced grade ≥3 complications. Conclusions: CT-based brachytherapy has the potential to become an essential treatment for vaginal recurrences of uterine cancer after hysterectomy as it can achieve good LC without increasing the rate of late complications for selected patients with less recurrences.

Purpose: To find out the simple relationship between Total Reference Air Kerma (TRAK) and various isodose volumes. Calculated isodose volumes were compared with experimental data for revised Manchester and International Commission on Radiation Units and measurements (ICRU)-89 Point A-based treatment plans. The accuracy of the formula was compared with the results of other relationships available in the literature.Materials and Methods: Dosimetric data from 62 intracavitary brachytherapy (ICBT) treatment plans of 31 patients with cervical cancer were studied. Each patient had treatment plans normalized to revised Manchester and ICRU-89 Points A (Aflange and Aicru89). For each treatment plan, TRAK values, V350, V700, V1050, and V1400 were obtained. The modeling curve was plotted between Isodose volume (Vd) and the ratio of d/TRAK obtained from Aflange plans to get a mathematical relation. The results of this formula were compared with the experimental data and outcomes of other formulas available in the literature. A paired-sample t-test was performed to assess the statistical significance.Results: In the case of revised Manchester-based Aflange normalization plans, the mean isodose volume of V350, V700, V1050, and V1400 were 285.98 ± 32.3 cm3, 101.96 ± 10.63 cm3, 52.71 ± 4.72 cm3, and 31.44 ± 2.33 cm3 respectively. Likewise, for ICRU-89 based Aicru89 normalization plans, the mean isodose volumes of V350, V700, V1050, and V1400 were 304.11 ± 26.17 cm3, 108.88 ± 8.29 cm3, 56.62 ± 3.69 cm3 and 34 ± 2.23 cm3 respectively. The mean difference was significant. The Mathematical relationship developed was [INLINE:1]. No correlation was found between TRAK and D0.1cm3,D2cm3 for organs at risk.Conclusions: The developed formula calculated isodose volumes within the accuracy of ± 3% in ICBT plans. [ABSTRACT FROM AUTHOR]

International commission of radiation units and measurement point doses to the bladder and rectum in carcinoma cervix patients treated with intracavitary brachytherapy in the department of radiotherapy. The aim: to evaluate two-dimensional point-based dose planning and three-dimensional computed tomography-based dose-volume parameters for high-dose-rate intracavitary brachytherapy of cervical cancer. Materials and methods: prospective study done between the years June 2018 to April 2020, a total of 50 prospectively registered women of non-metastatic carcinoma cervix treated with definitive concurrent chemo-radiotherapy followed by HDR intracavitary brachytherapy who met inclusion criteria were accrued in the study. All women in the study were treated with 50 Gy EBRT then assessment was done for response and adequacy for comfortable insertion of application. Brachytherapy procedure was performed under sedation in the lithotomy position. Results: Median age of the entire group was 54.5 years, majority of them were in their 5th (34 %) or 4th (28 %) decade. Pathologically, all were squamous cell carcinoma. Most common subtype was large cell non keratinizing type (64 %). Major bulk of the study is contributed by stage IIA, IIB, IIIB. All patients were treated with external beam radiotherapy of 50Gy in 25 fractions with 2Gy per fraction followed by high dose rate brachytherapy of 7 Gy per fraction for 3 fractions, one week apart to a total intracavitary brachytherapy dose of 21Gy. Conclusion: Results from the study suggests that rectum ICRU reference points can be surrogate markers for D2cc, but not for bladder and hence reporting should preferably be done in volumetric method rather than reference point doses [ABSTRACT FROM AUTHOR]

Background: The swift dose fall-off traits with distance from the applicators are the dominant advantage of brachytherapy. The differences in applicator designs will produce different dose distributions in intracavitary brachytherapy (ICBT) applications. Aim: The present study was aimed to find out the dosimetric differences for two type's applicators geometry in ICBT applications for carcinoma uterine cervix (Ca-Cx) performing three-dimensional computed tomography (3D-CT) image-based planning as per recent guidelines from the International Commission on Radiation Units and Measurements report-89. Materials and Methods: Retrospectively, 15 patients of Ca-Cx who have received ICBT treatment based on the 3D-CT image during 1st and 2nd fractions using fixed-geometry and flexible-geometry applicators respectively were selected for this study. For comparison of two type's applicators geometry the dose-volume parameters D100% and D90% of high-risk clinical target volume (HR-CTV), V400%, V200%, V150%, V100%, V50% (volume enclosing 400%, 200%, 150%, 100%, and 50% isodoseline of prescribed dose around target, respectively), and average point “A” dose were evaluated for target. While for organs at risk (bladder, rectum, and sigmoid colon) the dose-volume parameters D2cc, D1cc, and D0.1cc were recorded and evaluated. Results: Fixed-geometry applicator produces significantly lesser HR-CTV volume (P = 0.016

Purpose: The purpose of the study was to consider and calculate dosimetric parameters during treatment planning to improve radiobiological outcomes for cervical cancer patients treated with high-dose-rate (HDR) intracavitary brachytherapy (ICBT). Material and methods: In the present study, dose volume histograms (DVH) of 30 cervical cancer patients treated with HDR brachytherapy using computer tomography (CT)-based planning were analyzed. High-risk clinical target volume (HR-CTV) was contoured as the main target volume for all the patients, with an assumption that there was no presence of gross tumor at the time of brachytherapy. Values of target coverage volumes (100%, 150%, and 200%) were obtained from DVH, which was used to calculate different quality indices (QIs), including coverage index (CI), dose homogeneity index (DHI), overdose volume index (ODI), and dose non-uniformity ratio (DNR). Values of these QIs were further used to calculate tumor control probability (TCP). Statistical correlation between all QIs with TCP was established. Also, normal tissue complication probabilities for bladder (NTCP_B) and rectum (NTCP_R) were calculated. Results: The mean values of the various calculated parameters, including CI, DHI, ODI, DNR, TCP, NTCP_B and NTCP_R were 0.92 ±0.07, 0.26 ±0.10, 0.50 ±0.10, 0.74 ±0.10, 0.92 ±0.07, 0.08 ±0.25, and 0.36 ±0.27, respectively. Pearson's product moment correlation coefficient between CI, DHI, ODI, and DNR with regards to TCP was +0.85, -0.85, +0.84, and +0.85, respectively. Conclusions: The correlation between dosimetric and radiobiological parameters was found statistically significant, which shows the influence of dosimetric parameters on the radiobiological outcome. Therefore, these parameters should be considered during the treatment planning to improve the radiobiological outcome. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to evaluate clinical outcomes of MRI-guided adaptive brachytherapy (MR-IGABT) for each brachytherapy fraction in patients with locally advanced cervical cancer (LACC). Methods and Materials: A retrospective analysis was performed on 97 consecutive patients with LACC treated with 44.0–50.4 Gy external beam radiotherapy (EBRT) ± concurrent platinum-containing chemotherapy followed by 4 × 7 Gy MR-IGABT between September 2014 and April 2019. Intracavitary (IC)/interstitial (IS)/hybrid intracavitary and interstitial (IC/IS) brachytherapy was used in MR-IGABT. Brachytherapy planning and dose reporting followed the GEC-ESTRO recommendations. Clinical outcomes including overall survival (OS), cancer-specific survival (CSS), progression-free survival (PFS), local control (LC), and treatment-related toxicity evaluated by the RTOG criteria were analyzed. Kaplan–Meier and univariable and multivariable Cox regression analyses were used to analyze the prognostic factor. Results: Median follow-up was 21.1 months. Median dose to 90% (D90) of the high-risk clinical target volume (HR-CTV) was 91.7 Gy (range 76.7~107.2 Gy). Two-year OS, CSS, PFS, and LC were 83.5%, 84.1%, 71.1%, and 94.8%, respectively. Four patients (4.1%) suffered from grade 3 late gastrointestinal radiation toxicity, and no other grade 3 or greater radiation toxicity occurred. Initial HR-CTV was an independent factor of OS (p = 0.001, HR = 1.018/cm3), PFS (p = 0.012, HR = 1.012/cm3), and LC (p = 0.011, HR = 1.028/cm3). The HR-CTV D90 (p = 0.044, HR = 0.923/Gy) was an independent factor of PFS. Age was an independent factor of LC (p = 0.010, HR = 1.111/year). Conclusion: For patients with LACC, MR-IGABT was effective and safe. It showed favorable LC, OS, and minimal toxicity. Moreover, initial HR-CTV, HR-CTV D90, and age were significant prognostic factors. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic has caused a havoc across the globe, and has significantly affected oncology services, especially radiation therapy due to the need of social distancing as a measure for the pandemic mitigation. Brachytherapy, being an integral part of radiation therapy, posts a dilemma related to the practice of evidence-based oncology. It requires a significant amount of resources and personnel, thereby increasing the risk of exposure to the virus. There has been a significant amount of papers published providing the best available alternatives to external radiation; however, there is a lack of literature on the practice of brachytherapy. In times of the pandemic, deploying brachytherapy as a treatment modality can act as a double-edged sword and therefore, judicious use is warranted in such times of crisis. In this article, we provide a comprehensive review of the role of brachytherapy in various forms and different malignancy sites. [ABSTRACT FROM AUTHOR]

Nasopharyngeal brachytherapy is limited in part by the radiotolerance of nearby organs like the soft palate. This study explores several novel shielding designs for an intracavitary applicator to significantly reduce soft palate dose while adhering to the constraints of standard treatment procedure. The Monte Carlo code TOPAS is used to characterize each prototype under typical high-dose-rate treatment conditions. Mucosal surface dose maps are collected to evaluate the shields on their dose reduction to the central and soft palate planning points and uniformity in their shielding profile. Practicality with respect to patient comfort and pretreatment imaging is discussed. History-by-history standard deviations are calculated for each simulation. A design with elliptical tubing containing bundles of tantalum wires provides the most significant attenuation with 39% and 27% dose reduction to the center and soft palate locations, respectively. Another design utilizing miniature lead spheres loaded into a constructed cavity shows 27% and 24% dose reduction to the same locations while providing more uniform shielding and several practical benefits. Both shields are designed to be completely removable for applicator insertion and pretreatment imaging. The mean and maximum standard error of relative dose measurements was 0.36 and 1.14 percentage points, respectively. Each shielding design presented in this study provides a novel approach to safely and effectively shield healthy tissue during intracavitary nasopharyngeal brachytherapy. Analysis performed using Monte Carlo suggests that the design using metal spheres most practically shields the soft palate and should be advanced to the next stages of clinical optimization. [ABSTRACT FROM AUTHOR]

PurposeThis study aims to evaluate clinical outcomes of MRI-guided adaptive brachytherapy (MR-IGABT) for each brachytherapy fraction in patients with locally advanced cervical cancer (LACC).Methods and MaterialsA retrospective analysis was performed on 97 consecutive patients with LACC treated with 44.0–50.4 Gy external beam radiotherapy (EBRT) ± concurrent platinum-containing chemotherapy followed by 4 × 7 Gy MR-IGABT between September 2014 and April 2019. Intracavitary (IC)/interstitial (IS)/hybrid intracavitary and interstitial (IC/IS) brachytherapy was used in MR-IGABT. Brachytherapy planning and dose reporting followed the GEC-ESTRO recommendations. Clinical outcomes including overall survival (OS), cancer-specific survival (CSS), progression-free survival (PFS), local control (LC), and treatment-related toxicity evaluated by the RTOG criteria were analyzed. Kaplan–Meier and univariable and multivariable Cox regression analyses were used to analyze the prognostic factor.ResultsMedian follow-up was 21.1 months. Median dose to 90% (D90) of the high-risk clinical target volume (HR-CTV) was 91.7 Gy (range 76.7~107.2 Gy). Two-year OS, CSS, PFS, and LC were 83.5%, 84.1%, 71.1%, and 94.8%, respectively. Four patients (4.1%) suffered from grade 3 late gastrointestinal radiation toxicity, and no other grade 3 or greater radiation toxicity occurred. Initial HR-CTV was an independent factor of OS (p = 0.001, HR = 1.018/cm3), PFS (p = 0.012, HR = 1.012/cm3), and LC (p = 0.011, HR = 1.028/cm3). The HR-CTV D90 (p = 0.044, HR = 0.923/Gy) was an independent factor of PFS. Age was an independent factor of LC (p = 0.010, HR = 1.111/year).ConclusionFor patients with LACC, MR-IGABT was effective and safe. It showed favorable LC, OS, and minimal toxicity. Moreover, initial HR-CTV, HR-CTV D90, and age were significant prognostic factors.

Purpose: To investigate the effect of different source dwell positions on dose distribution in the treatment of cervical cancer with brachytherapy., Methods: Treatment planning data for cervical cancer patients were used. Treatment plans were created at 1 mm intervals, varying up to 5 mm. For intracavitary brachytherapy and intracavitary and interstitial brachytherapy, the following dose parameters were evaluated: 90% high-risk clinical target volume (HR-CTV D 90% ), rectum 2 cm 3 dose (Rectum D 2 cc ), small intestine 2 cm 3 dose (Small D 2 cc ), sigmoid colon 2 cm 3 dose (Sigmoid D 2 cc ), bladder 2 cm 3 dose (Bladder D 2 cc ), point A dose., Results: In intracavitary brachytherapy, the HR-CTV D 90% , Rectum D 2 cc , Small D 2 cc , and Sigmoid D 2 cc doses increased as the source dwell position changed in the direction. On the other hand, the dose of Bladder D 2 cc increased when the source position changed in the outward direction. The same trend was observed in the case of intracavitary and interstitial brachytherapy., Conclusion: It was shown that a 1 mm change in the source dwell position can affect the dose by up to 2% or more. The accuracy of the source dwell position is very important and should be checked before using the device.

Purpose: To evaluate feasibility and safety of execution of optimized intra-cavitary brachytherapy (ICBT) plan of first fraction in subsequent fractions in high-volume, low-resource centers. Material and methods: This non-randomized prospective study included 30 cervical cancer patients, who underwent 4 fractions of high-dose-rate (HDR)-ICBT in 2 applications, one week apart, 2 fractions per application delivered on two consecutive days. Computed tomography (CT) simulation was done before each fraction, organs at risk (OARs) were contoured on all sets of CT images. Optimized plans were generated for each set of CT images and executed for the treatment. Test treatment plans were retrospectively generated by applying first treatment fraction's dwell times adjusted for decay, and dwell positions of the applicator for subsequent treatment fractions paired t-test was performed to analyze D2cc dose variations of OARs among the paired sets of plans. Results: Comparison between the plans showed daily plans provided lower D2cc to OARs than test plans. In intraapplication plan comparison, there was a significant dose reduction to 2 cc sigmoid (p = 0.021) and bladder (p = 0.007) in daily plan. Mean D2cc of optimized and unoptimized plans were 361.35 ±114.01 and 411.70 ±152.73 for sigmoid, and 511.23 ±85.47 cGy and 553.57 ±111.23 cGy for bladder, respectively. In inter-application, D2cc rectum and sigmoid demonstrated a statistically significant dose variation (p = 0.002) and (p = 0.007), with mean D2cc rectum of optimized and unoptimized plans being 401.06 ±83.53 cGy and 452.46 ±123.97 cGy, and of 2 cc sigmoid 340.84 ±117.90 cGy and 387.79 ±141.36 cGy, respectively. Conclusions: Fractionated HDR brachytherapy amounts to significant variation in OAR doses if re-simulation and re-plan is not performed for every fraction and ICBT application. Therefore, plan of the day with optimization of the doses to target and OARs must be followed for each fraction. [ABSTRACT FROM AUTHOR]

Intracavitary brachytherapy using High-Dose-Rate (HDR) and Low-dose-rate (LDR) in cervical cancer has been utilized. We report the long-term final results of a large randomized trial in terms of toxicities and efficacy. Between 1996 to 2005, 816 patients were randomized to LDR (n = 441 patients) or HDR brachytherapy (n = 369 patients) stratified by FIGO Stage grouping. Patients with Stage I-II received external irradiation of 40 Gy in 20 fractions (with midline block (MLB)) followed by either 2 LDR Intracavitary applications of 30 Gy to point A (2–3 weeks apart) or 5 HDR Intracavitary applications of 7 Gy to point A once weekly. Patients with Stage III received 50 Gy in 25 fractions (with MLB after 40 Gy) followed by either one application of LDR 30 Gy to point A or three applications of HDR 7 Gy to point A once weekly. With a median follow-up was 64 months (interquartile range [IQR]: 21 - 111), moderate to severe rectal and bladder complications were higher in LDR arm as compared to HDR arm (9.7% vs. 3.6%; p = 0.02) and (10.5% vs. 5.5%; p = 0.06) for Stage I-II. No difference in rectal or bladder complications for Stage III patients. Disease free and overall survivals were similar in both the arms for all stages. HDR intracavitary brachytherapy with 7 Gy per fraction weekly is superior to LDR in terms of late rectal and bladder complications. Local control rates and survivals are similar irrespective of stages. [ABSTRACT FROM AUTHOR]

Despite the excellent clinical outcomes from brachytherapy treatments compared with other modalities and the low associated costs, there have been reports of a decline in utilization of brachytherapy. The aim of this study was to investigate in detail the trend in utilization of brachytherapy in the province of Québec, Canada, from 2011 to 2019. All radiotherapy clinics in the province of Quebec, and among these the clinics that provide brachytherapy treatments, were identified. This observational retrospective cohort study involved analysis of data compiled by the Ministère de la Santé et des Services Sociaux du Québec for the period of 2011 to end of 2019 on all brachytherapy procedures performed in the province of Quebec. Time series graphs were used to describe the number of high dose rate (HDR) and low dose rate (LDR) brachytherapy treatments during the studied time period. Statistical analysis was conducted using R statistical software. Between 2011 and 2019, 12 hospitals in the province of Québec provided radiotherapy treatments, and all of them offered brachytherapy services. The median annual number of brachytherapy sessions was 4413 (range 3930-4829). HDR brachytherapy represented over 90% of all brachytherapy treatments throughout the study period. Significant changes over time were observed in the number of treatments: at least 5% change was seen only for the two most common subtypes of brachytherapy, HDR interstitial and HDR intracavitary, with an increase of 9.6% and a decrease of 9.2%, respectively. The use of other subtypes of brachytherapy (HDR-plesiotherapy, LDR-interstitial, LDR-intracavitary, LDR-eye plaque) was stable between 2011 and 2019, with ≤ 2.5% variation. This study demonstrates an overall steady use of brachytherapy between 2011 and 2019 in Quebec. Brachytherapy offers numerous advantages for the treatment of diverse cancer sites. Although more sophisticated external beam radiotherapy treatments have emerged in the last decades, the precision and cost-effectiveness of brachytherapy remain unbeaten. To ensure the continued use and availability of brachytherapy, governments must put in place policies and regulations to that effect. Training and exposure of future health care professionals to brachytherapy within Quebec and Canada is essential to provide all patients the same access to this life saving modality. [ABSTRACT FROM AUTHOR]

Background: Image-guided adaptive brachytherapy shows the ability to deliver high doses to tumors while sparing normal tissues. However, interfraction dose delivery introduces uncertainties to high dose estimation, which relates to normal tissue toxicity. The purpose of this study was to investigate the high-dose regions of two applicator approaches in brachytherapy.Method: For 32 cervical cancer patients, the CT images from each fraction were wrapped to a reference image, and the displacement vector field (DVF) was calculated with a hybrid intensity-based deformable registration algorithm. The fractional dose was then accumulated to calculate the position and the overlap of high dose (D2cc) during multiple fractions.Result: The overall Dice similarity coefficient (DSC) of the deformation algorithm for the bladder and the rectum was (0.97 and 0.91). No significant difference was observed between the two applicators. However, the location of the intracavitary brachytherapy (ICBT) high-dose region was relatively concentrated. The overlap volume of bladder and rectum D2cc was 0.42 and 0.71, respectively, which was higher than that of interstitial brachytherapy (ISBT) (0.26 and 0.31). The cumulative dose was overestimated in ISBT cases when using the GEC-recommended method. The ratio of bladder and rectum D2cc to the GEC method was 0.99 and 1, respectively, which was higher than that of the ISBT method (0.96 and 0.94).Conclusion: High-dose regions for brachytherapy based on different applicator types were different. The 3D-printed ICBT has better high-dose region consistency than freehand ISBT and hence is more predictable. [ABSTRACT FROM AUTHOR]

Purpose: In this study, we propose combining three‐dimensional (3D) transrectal ultrasound (TRUS) and 3D transabdominal ultrasound (TAUS) images of gynecologic brachytherapy applicators to leverage the advantages of each imaging perspective, providing a broader field‐of‐view and allowing previously obscured features to be recovered. The aim of this study was to evaluate the feasibility of fusing these 3D ultrasound (US) perspectives based on the applicator geometry in a phantom prior to clinical implementation. Methods: In proof‐of‐concept experiments, 3D US images of application‐specific multimodality pelvic phantoms were acquired with tandem‐and‐ring and tandem‐and‐ovoids applicators using previously validated imaging systems. Two TRUS images were acquired at different insertion depths and manually fused based on the position of the ring/ovoids to broaden the TRUS field‐of‐view. The phantom design allowed "abdominal thickness" to be modified to represent different body habitus and TAUS images were acquired at three thicknesses for each applicator. The merged TRUS images were then combined with TAUS images by rigidly aligning applicator components and manually refining the registration using the positions of source channels and known tandem length, as well as the ring diameter for the tandem‐and‐ring applicator. Combined 3D US images were manually, rigidly registered to images from a second modality (magnetic resonance (MR) imaging for the tandem‐and‐ring applicator and X‐ray computed tomography (CT) for the tandem‐and‐ovoids applicator (based on applicator compatibility)) to assess alignment. Four spherical fiducials were used to calculate target registration errors (TREs), providing a metric for validating registrations, where TREs were computed using root‐mean‐square distances to describe the alignment of manually identified corresponding fiducials. An analysis of variance (ANOVA) was used to identify statistically significant differences (p < 0.05) between the TREs for the three abdominal thicknesses for each applicator type. As an additional indicator of geometric accuracy, the bladder was segmented in the 3D US and corresponding MR/CT images, and volumetric differences and Dice similarity coefficients (DSCs) were calculated. Results: For both applicator types, the combination of 3D TRUS with 3D TAUS images allowed image information obscured by the shadowing artifacts under single imaging perspectives to be recovered. For the tandem‐and‐ring applicator, the mean ± one standard deviation (SD) TREs from the images with increasing thicknesses were 1.37 ± 1.35 mm, 1.84 ± 1.22 mm, and 1.60 ± 1.00 mm. Similarly, for the tandem‐and‐ovoids applicator, the mean ± SD TREs from the images with increasing thicknesses were 1.37 ± 0.35 mm, 1.95 ± 0.90 mm, and 1.61 ± 0.76 mm. No statistically significant difference was detected in the TREs for the three thicknesses for either applicator type. The mean volume differences for the bladder segmentations were 3.14% and 2.33% and mean DSCs were 87.8% and 87.7% for the tandem‐and‐ring and tandem‐and‐ovoids applicators, respectively. Conclusions: In this proof‐of‐concept study, we demonstrated the feasibility of fusing 3D TRUS and 3D TAUS images based on the geometry of tandem‐and‐ring and tandem‐and‐ovoids applicators. This represents a step toward an accessible and low‐cost 3D imaging method for gynecologic brachytherapy, with the potential to extend this approach to other intracavitary configurations and hybrid applicators. [ABSTRACT FROM AUTHOR]

We aimed to investigate the added value of interstitial brachytherapy (IS-BT) over classical intracavitary BT (IC-BT) in terms of target coverage and organ at risk (OAR) sparing among patients for whom an optimal dose distribution could not be provided without IS-ICBT and also to determine if the magnitude advantage provided by IS-BT is similar in patients smaller (<30 cm³) and larger (≥30 cm³) high-risk clinical target volume (CTVHR). METHODS 24 patients treated with IS-ICBT were included in this study. IS-BT was performed 76 of 93 BT fractions. For each patient, two additional IC-BT planning were created: (1) ICBTTarget-focused plan: The priority was adequate coverage of CTVHR. Then, the OARs were spared as much as possible. (2) ICBTOARs-focused plan: The priority was given to the OAR sparing. Then, highest CTVHR coverage was tried to achieve within the allowed OAR dose limits. The IS-ICBT plans were compared with these two plans in terms of target coverage and OAR doses. RESULTS 13 patients had large and 11 patients had small CTVHR. In IS-ICBT plans, EQD210 CTVHR D90 doses were significantly higher compared with ICBTOARs-focused plans (Δdose: 10.5±6.2 Gy, p<0.001), whereas EQD23 OAR D2cc doses were significantly lower compared with ICBTTarget-focused plans (Average Δdose, bladder: 24.5±25.9 Gy [p<0.001], rectum: 7.6±9.7 Gy [p=0.001], sigmoid: 18.3±15.3 Gy [p<0.001]). There was no significant difference between patients with small and large CTVHR in terms of Δdoses of both target and OARs. CONCLUSION IS-BT provides significant therapeutic advantage over IC-BT for patients both with small and large CTVHR. [ABSTRACT FROM AUTHOR]

Aim: To investigate the ease of tandem application and external os identification by giving sublingual misoprostol before initiation of intracavitary brachytherapy in cancer cervix patients.Materials and Methods: 36 patients with cervical cancer stage IIIB which were supposed to undergo intracavitary brachytherapy(ICBT) were randomly divided into 2 subgroups, group A patients receiving misoprostol and group B not receiving misoprostol.Misoprostol 400 mcg was given sublingually 3 hrs prior to the procedure. The efficacy of the drug was measured as per the ease of identification of os and easier tandem application and amount of bleeding during procedure.Results: Application of tandem and identification of external os was easier and amount of bleeding was also less in patients that were administered sublingual misoprostol.Conclusion: Sublingual Misoprostol given before ICBT helps in cervical ripening and thus leads to easier os recognition and central tandem application and reduce overall anaesthesia time. [ABSTRACT FROM AUTHOR]